U.S. Pat. No. 6,930,818 discloses an electrophoretic display based on the microcup technology. The patent describes the manufacture of microcups as display cells, by microembossing or imagewise exposure. The microcups are then filled with an electrophoretic fluid comprising charged pigment particles dispersed in a solvent or solvent mixture.
The top openings of the microcups traditionally may have the same size and shape and such microcups spread across the entire display surface. For example, all of the microcups may have a top opening of a square shape or all of the microcups may have a top opening of a hexagonal shape, on the viewing side.
For this traditional type of design, because the microcups are not randomized, the Moiré pattern can occur when the microcup film is laminated to a TFT backplane which also has a repeatable regular pattern. If a color filter is utilized in such a display device, the Moiré pattern is even more severe because the color filter also has a repeatable regular pattern.
By rotating the microcups to a less severe angle, the Moiré phenomenon may be reduced. However, such structural changes could reduce the cutting yield and also because the rotation angle must be precise, it could increase the processing cost.